As CBS2’s Lou Young reported, drug sales were going down among the stacks in the White Plains Public Library.

The Westchester D.A. said it was Willie James Edward’s territory for serving drug addicts — he was among 18 arrested on Thursday.

The District Attonrey stood with federal agents and cops from all over Westchester to announce the unraveling of several suburban heroin networks — a priority following a string of fatal overdoses last summer.

“These arrests dismantled a group of heroin dealers that pumped narcotics into quiet residential neighborhoods 24 hours a day, 7 days a week,” Westchester District Attorney Anthony Scarpino said.

A total of $100,00 in cash, 2.5-kilos of smack, 7,000 glassine envelopes, and guns to protect it all were found.

“Each of these guys had upwards of 25 customers that they dealt to in this area,” Scarpino said.

There were reportedly heroin locations in White Plains and Yonkers. Each dealer allegedly worked independently, and didn’t know the others, but their supply was traced back to the Bronx — a guy named Luis Castro who is now in federal custody.

The investigation also led to the April arrest of Gjon Krasnici, a teacher at the Virginia Road Elementary School in Valhalla, WCBS 880’s Marla Diamond reported.

CBS2 has been told there are now about a hundred heroin users without a supplier.

The hope is that a few users will now choose that route, knowing they’re on the police radar.

“Since we picked up the dealers at this particular time, if you’re in need and you think you need help this is a good time to come. Our CLEAR program will guide you in the right direction. There’s not going to be any expense to you and it’s really no questions asked,” White Plains Public Safety Commissioner David Chong said.

The lesson learned from America’s long fruitless drug war is that arresting dealers is all well and good, but where there’s a demand there will always be a supply.

The D.A. said the heroin they’ve been encountering lately is so powerful, it’s taking multiple doses of Narcan to reverse overdose symptoms on the street.